Carbon atom having 4 valence electrons can form 4 covalent Bonds. As there are 3 carbon atoms in the molecule connected to each other by single bond. So the terminal carbons are left with 3 unbonded electrons and the central carbon is left with two unbonded electrons. So, terminal carbons will further form three single bonds with 3 hydrogen atoms each and the central carbon will form two covalent bonds with 2 hydrogen atoms, i.e.
H₃C-CH₂-CH₃
Result:
This Molecule contains 8 Hydrogen atoms.